類型錯誤：ajtokenSaleInstance.tokensSold 不是函式

我在 youtube 上關注本教程“在乙太坊上編寫你自己的加密貨幣（完整）”我停留在我試圖返回 TokensSold 值的部分之一，但我不斷收到錯誤消息

“TypeError：ajtokenSaleInstance.tokensSold 不是函式”

對講師同樣有效的是參考連結 https://youtu.be/XdKv5uwEk5A?t=22108

下面是我的程式碼，請幫忙

App = {
web3Provider: null,
contracts: {},
account: '0x0', 
loading: false,
tokensSold:0,
tokenPrice:1000000000000000,    
tokensAvilable : 750000,
init : function() {
   console.log('app started');
   return App.intiWeb3();
},

intiWeb3 : function() {
   if (typeof web3 !== 'undefined') {
       //console.log('web3  defined');
       // if there is already instance of web3 is present e.g. from metamask
       App.web3Provider = web3.currentProvider;
       //console.dir(web3.currentProvider);
       web3 = new Web3(web3.currentProvider);
   } else {
       // Specify default instance if no web3 instance is provided
       //console.log('web3 not defined')
       App.web3Provider = new Web3.providers.httpProvider('http://localhost:7545');
       web3 = new Web3(App.web3Provider);
   }

   return App.initContracts();

},

initContracts: function() {
   $.getJSON("AjTokenSale.json", function(ajtokensale) {
       App.contracts.AjTokenSale = TruffleContract(ajtokensale);
       App.contracts.AjTokenSale.setProvider(App.web3Provider);
       App.contracts.AjTokenSale.deployed().then(function(ajtokensale){
           //return ajtokensale.tokenPrice()
           //console.dir('dir is' + ajtokensale.tokenPrice());
           console.log('AJTOKEN sale address is ' + ajtokensale.address);
           //console.dir(ajtokensale);
       }); 
   }).done(function() {
     $.getJSON("AjToken.json", function(ajtoken) {
       App.contracts.AjToken = TruffleContract(ajtoken);
       App.contracts.AjToken.setProvider(App.web3Provider);
       App.contracts.AjToken.deployed().then(function(ajtoken){
           console.log('AJ token  address ' + ajtoken.address);
       });
       return App.render();
     });
    });

},

render: function() {
   if(App.loading) {
       return;
   }
   App.loading = true;

   var loader = $('#loader');
   var content = $('#content');

   loader.show();
   content.hide();

   // load account data
   //var accounts = web3.eth.getallAccounts

   web3.eth.getCoinbase(function(err, account) {
       if(account) {
           App.account = account;
           $('#accountAddress').html("Your account: " + account);
       } else {
           console.log('Address is null, err is '+err)
       }
   });


   //$('#accountAddress').html("Your account: " + accounts[0]);

   App.contracts.AjTokenSale.deployed().then(function(instance) {
       ajtokenSaleInstance = instance;
       //console.log(ajtokenSaleInstance);
       return ajtokenSaleInstance.tokenPrice();
   }).then(function(tokenPrice) {
       App.tokenPrice = tokenPrice.toNumber();
       //console.log('tokenPrice ' + tokenPrice.toNumber());
       $('.token-price').html(web3.fromWei(App.tokenPrice, 'ether'));
       return ajtokenSaleInstance.tokensSold();            
   }).then(function(tokensSold) {
       //App.tokensSold = tokensSold.toNumber(); 
       App.tokensSold = parseInt(tokensSold).toNumber(); 
       //App.tokensSold = 680000;
       $('.tokens-sold').html(App.tokensSold);
       $('.token-available').html(App.tokensAvilable);

       var progressPercent = (Math.ceil(App.tokensSold) / App.tokensAvilable)* 100;
       $('#progress').css('width', progressPercent+'%');

       // load token contract 

       App.contracts.AjToken.deployed().then(function(instance) {
           ajTokenInstance = instance;
           return ajTokenInstance.balanceOf(App.account);
       }).then(function(balance) {
           $('.ajtoken-balance').html(balance.toNumber());
           App.loading = false;
           loader.hide();
           content.show();
       })
   });

   //.done(function() {


   //});

},

buyTokens:  function() {
   $('#content').hide();
   $('#loader').show();

   var numberOfToken = $('#numberOfToken').val();
   App.contracts.AjTokenSale.deployed(function(instance) {
       return instance.buyTokens(numberOfToken, {
           from: App.account, 
           value: numberOfToken * App.tokenPrice,
           gas:500000
       });
   }).then(function(result) {
       console.log("Tokens bought..");
       $('form').trigger('reset');
       $('#loader').hide();
       $('#content').show();
   })
}}


$(function() {
$(window).load(function() {
   App.init();
});
}); 

下面是我的 AjTokenSale 程式碼

pragma solidity ^0.4.2;
import './AjToken.sol';

contract AjTokenSale {
address admin;
AjToken public tokenContract;
uint256 public tokenPrice;
uint256 public tokenSold;

event Sell(address _buyer, uint256 _amount);

function AjTokenSale(AjToken _tokenContract, uint256 _tokenPrice) public {
   //Assign an Admin
   admin = msg.sender;
   //Token contract
   tokenContract = _tokenContract;
   //Set the Token Price
   tokenPrice = _tokenPrice;
}    

//Multiply

function multiply(uint x, uint y) internal pure returns(uint z) {

   require (y == 0 || (z = x * y)/y == x);

}

//Buy toekns
function buyTokens(uint256 _numberOfTokens) public payable {
   //Value is equal to token Price

   require(msg.value == multiply(_numberOfTokens , tokenPrice));

   //Require that contract has the enough toekns

   require(tokenContract.balanceOf(this) >= _numberOfTokens);

   //Require that a transfer is successful
   require(tokenContract.transfer(msg.sender, _numberOfTokens));
   //Keep track of tokenSold
   tokenSold += _numberOfTokens;
   //Trigger sell event
   Sell(msg.sender, _numberOfTokens); 
}

//End token sale 

function endSale() public {
   //only Admin can end the sale
   require(msg.sender == admin);       
   // Transfer remaining tokens back to admin
   require(tokenContract.transfer(admin, tokenContract.balanceOf(this))); 
   admin.transfer(address(this).balance);

}

}

下面是 AjToken 程式碼

pragma solidity ^0.4.2;

contract AjToken {
string  public name = "AJ Token";
string  public symbol = "AJ";
string  public standard = "AJ Token V1.0 standard";
uint256 public totalSupply;

event Transfer(
   address indexed _from,
   address indexed _to,
   uint256 _value
);

event Approval(
   address indexed _owner,
   address indexed _spender,
   uint256 _value
);

mapping(address => uint256) public balanceOf;
mapping(address => mapping(address => uint256)) public allowance;

function AjToken (uint256 _initialSupply) public {
   balanceOf[msg.sender] = _initialSupply;
   totalSupply = _initialSupply;
}

function transfer(address _to, uint256 _value) public returns (bool success) {
   require(balanceOf[msg.sender] >= _value);

   balanceOf[msg.sender] -= _value;
   balanceOf[_to] += _value;

   Transfer(msg.sender, _to, _value);

   return true;
}

function approve(address _spender, uint256 _value) public returns (bool success) {
   allowance[msg.sender][_spender] = _value;

   Approval(msg.sender, _spender, _value);

   return true;
}

function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
   require(_value <= balanceOf[_from]);
   require(_value <= allowance[_from][msg.sender]);

   balanceOf[_from] -= _value;
   balanceOf[_to] += _value;

   allowance[_from][msg.sender] -= _value;

   //call transfer event 

   //finally, return boolean


   Transfer(_from, _to, _value);

   return true;
}
}

看起來像一個錯字。

錯誤（額外的“s”）：

“TypeError：ajtokenSaleInstance.token s Sold 不是函式”

契約：

uint256 公共代幣已售出；

引用自：https://ethereum.stackexchange.com/questions/63428